rpc: "addpeeraddress tried" return error on failure

When trying to add an address to the IP address manager tried table,
it's first added to the new table and then moved to the tried table.
Previously, adding a conflicting address to the address manager's
tried table with test-only `addpeeraddress tried=true` RPC would
return `{ "success": true }`. However, the address would not be added
to the tried table, but would remain in the new table. This caused,
e.g., issue 28964.

This is fixed by returning `{ "success": false, "error":
"failed-adding-to-tried" }` for failed tried table additions. Since
the address remaining in the new table can't be removed (the address
manager interface does not support removing addresses at the moment
and adding this seems to be a bigger effort), an error message is
returned. This indicates to a user why the RPC failed and allows
accounting for the extra address in the new table.

Also:
To check the number of addresses in each addrman table,
the addrman checks were re-run and the log output of this check
was asserted. Ideally, logs shouldn't be used as an interface
in automated tests. To avoid asserting the logs, use the getaddrmaninfo
and getrawaddrman RPCs (which weren't implemented when the test was added).
Removing the "getnodeaddress" calls would also remove the addrman checks
from the test, which could reduce the test coverage. To avoid this,
these are kept.

Author: 0xB10C

src/rpc/net.cpp

@@ -951,7 +951,7 @@ static RPCHelpMan getnodeaddresses()
 static RPCHelpMan addpeeraddress()
 {
     return RPCHelpMan{"addpeeraddress",
-        "\nAdd the address of a potential peer to the address manager. This RPC is for testing only.\n",
+        "Add the address of a potential peer to an address manager table. This RPC is for testing only.",
         {
             {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The IP address of the peer"},
             {"port", RPCArg::Type::NUM, RPCArg::Optional::NO, "The port of the peer"},
@@ -960,7 +960,8 @@ static RPCHelpMan addpeeraddress()
         RPCResult{
             RPCResult::Type::OBJ, "", "",
             {
-                {RPCResult::Type::BOOL, "success", "whether the peer address was successfully added to the address manager"},
+                {RPCResult::Type::BOOL, "success", "whether the peer address was successfully added to the address manager table"},
+                {RPCResult::Type::STR, "error", /*optional=*/true, "error description, if the address could not be added"},
             },
         },
         RPCExamples{
@@ -989,8 +990,13 @@ static RPCHelpMan addpeeraddress()
             success = true;
             if (tried) {
                 // Attempt to move the address to the tried addresses table.
-                addrman.Good(address);
+                if (!addrman.Good(address)) {
+                    success = false;
+                    obj.pushKV("error", "failed-adding-to-tried");
+                }
             }
+        } else {
+            obj.pushKV("error", "failed-adding-to-new");
         }
     }
 

test/functional/rpc_net.py

@@ -340,26 +340,52 @@ def test_addpeeraddress(self):
         assert_raises_rpc_error(-1, "JSON integer out of range", self.nodes[0].addpeeraddress, address="1.2.3.4", port=-1)
         assert_raises_rpc_error(-1, "JSON integer out of range", self.nodes[0].addpeeraddress, address="1.2.3.4", port=65536)
 
+        self.log.debug("Test that adding a valid address to the new table succeeds")
+        assert_equal(node.addpeeraddress(address="1.0.0.0", tried=False, port=8333), {"success": True})
+        addrman = node.getrawaddrman()
+        assert_equal(len(addrman["tried"]), 0)
+        new_table = list(addrman["new"].values())
+        assert_equal(len(new_table), 1)
+        assert_equal(new_table[0]["address"], "1.0.0.0")
+        assert_equal(new_table[0]["port"], 8333)
+
+        self.log.debug("Test that adding an already-present new address to the new and tried tables fails")
+        for value in [True, False]:
+            assert_equal(node.addpeeraddress(address="1.0.0.0", tried=value, port=8333), {"success": False, "error": "failed-adding-to-new"})
+        assert_equal(len(node.getnodeaddresses(count=0)), 1)
+
         self.log.debug("Test that adding a valid address to the tried table succeeds")
         self.addr_time = int(time.time())
         node.setmocktime(self.addr_time)
         assert_equal(node.addpeeraddress(address="1.2.3.4", tried=True, port=8333), {"success": True})
-        with node.assert_debug_log(expected_msgs=["CheckAddrman: new 0, tried 1, total 1 started"]):
-            addrs = node.getnodeaddresses(count=0)  # getnodeaddresses re-runs the addrman checks
-            assert_equal(len(addrs), 1)
-            assert_equal(addrs[0]["address"], "1.2.3.4")
-            assert_equal(addrs[0]["port"], 8333)
+        addrman = node.getrawaddrman()
+        assert_equal(len(addrman["new"]), 1)
+        tried_table = list(addrman["tried"].values())
+        assert_equal(len(tried_table), 1)
+        assert_equal(tried_table[0]["address"], "1.2.3.4")
+        assert_equal(tried_table[0]["port"], 8333)
+        node.getnodeaddresses(count=0)  # getnodeaddresses re-runs the addrman checks
 
         self.log.debug("Test that adding an already-present tried address to the new and tried tables fails")
         for value in [True, False]:
-            assert_equal(node.addpeeraddress(address="1.2.3.4", tried=value, port=8333), {"success": False})
-        assert_equal(len(node.getnodeaddresses(count=0)), 1)
-
-        self.log.debug("Test that adding a second address, this time to the new table, succeeds")
+            assert_equal(node.addpeeraddress(address="1.2.3.4", tried=value, port=8333), {"success": False, "error": "failed-adding-to-new"})
+        assert_equal(len(node.getnodeaddresses(count=0)), 2)
+
+        self.log.debug("Test that adding an address, which collides with the address in tried table, fails")
+        colliding_address = "1.2.5.45"  # grinded address that produces a tried-table collision
+        assert_equal(node.addpeeraddress(address=colliding_address, tried=True, port=8333), {"success": False, "error": "failed-adding-to-tried"})
+        # When adding an address to the tried table, it's first added to the new table.
+        # As we fail to move it to the tried table, it remains in the new table.
+        addrman_info = node.getaddrmaninfo()
+        assert_equal(addrman_info["all_networks"]["tried"], 1)
+        assert_equal(addrman_info["all_networks"]["new"], 2)
+
+        self.log.debug("Test that adding an another address to the new table succeeds")
         assert_equal(node.addpeeraddress(address="2.0.0.0", port=8333), {"success": True})
-        with node.assert_debug_log(expected_msgs=["CheckAddrman: new 1, tried 1, total 2 started"]):
-            addrs = node.getnodeaddresses(count=0)  # getnodeaddresses re-runs the addrman checks
-            assert_equal(len(addrs), 2)
+        addrman_info = node.getaddrmaninfo()
+        assert_equal(addrman_info["all_networks"]["tried"], 1)
+        assert_equal(addrman_info["all_networks"]["new"], 3)
+        node.getnodeaddresses(count=0)  # getnodeaddresses re-runs the addrman checks
 
     def test_sendmsgtopeer(self):
         node = self.nodes[0]